A Comparative Study of the Basin and Range and the Extended Eastern North China Block

We have undertaken a comparative analysis of the Basin and Range and Eastern North China block by compiling a variety of data and evaluating previous studies. As a result of a large Chinese research project, many new data exist in North China, and the Basin and Range has been the focus of many investigations for years. Both areas are part of large-scale extensional tectonic regimes that span all or most of the Cenozoic and are presently active. However, much of each province was once cratonal and has thus been decratonized. The tectonic evolution of these areas is similar, which provides some insight into what might cause extensional regimes to form. Geographically these areas are similar with stable block uplift, extension, and strike-slip deformation at approximately the same latitudes. The amounts of extension in the Northern Basin and Range and Eastern North China block are comparable at ~ 10% - 30% since the beginning of the Cenozoic. However, current extension rates are greater for the Basin and Range, and the Central Basin and Range is highly extended. Both areas exhibit similar extension style in that they are characterized by rotated crustal blocks and half grabens. Geophysical data suggest that both areas experienced periods of mantle upwelling that resulted in comparable amounts of thinning in the crust and mantle lithosphere. Moho depths are on average greater for the Eastern North China block, although depths in the Bohai basin and the Basin and Range are both ~30 km.